Photo/Illutration The Asahi Shimbun

Population trends in Japan brought on primarily by the rapid aging of society, coupled with a dwindling birthrate, will require a drastic redistribution of seat numbers for the Lower House to maintain some semblance of equality in the value of a vote.

Calculations by The Asahi Shimbun based on future population projections by the National Institute of Population and Social Security Research resulted in a scenario for 2040 that would see 16 seats being given to six prefectures in urban areas with the same number being reduced in 16 rural prefectures.

Under a 2016 legal revision of the law regarding the Lower House electoral system, reapportionment based on what is called the Adams method will have to be undertaken every 10 years based on latest census figures.

The revision specified that the next Lower House election must be conducted after reapportionment by applying the Adams method for the first time.

The method, designed to distribute seats to closely match population differences, is one of a number available that gives rural areas a larger number of seats than would a strict distribution based solely on population.

Moves already are under way to add 10 seats while reducing the same number for the next Lower House election.

The reapportionment measure is in response to court rulings that found Lower House elections were held in a state of unconstitutionality due to differences in the value of a vote.

The Takamatsu High Court handed down a ruling to this effect this week for the Lower House election held in October when the vote difference was a maximum 2.08 times between the least and most populous districts.

Under the Asahi calculation for 2040, the vote difference would cap at 1.78 times.

That calculation would give Tokyo eight more seats in 2040 than the 25 it now has. Neighboring populous Kanagawa Prefecture would gain three seats, Aichi two and Saitama, Chiba and Fukuoka one each, under the Asahi calculation.

The ruling Liberal Democratic Party played a leading role in pushing the 2016 legal revision. However, disgruntlement has emerged among LDP lawmakers, especially those in prefectures that are projected to lose seats in the next Lower House election.

In the view of experts, moving toward equality in the value of a vote is of greater importance than allowing the voices of rural areas to be heard.

“There are projections that even the Adams method will not be able to reduce the vote difference to under 2 times in the future,” noted Reiko Oyama, a professor of political science at Tokyo’s Komazawa University.

Rather than tinker with the electoral system through reapportionment every 10 years, she called for drastically altering the electoral system for both Diet chambers to ensure not only vote equality but to also allow rural areas to have their say in Diet proceedings.

“Rather than decide based on the wishes of incumbent lawmakers, a third-party panel should consider what would be the best way to change the electoral system,” Oyama said.

Related News